Method of making a buffing wheel



1965 G. R. CHURCHILL METHOD OF MAKING A BUFFINQ WHEEL Original Filed May18, 1960 3 Sheets-Sheet l INVENTOR G yg Church/W ATTORNEY Oct. 19, 1965R. CHURCHILL 3,212,819

METHOD OF MAKING A BUFFING WHEEL Original Filed May 18, 1960 3Sheets-She et 2 IN VE N TOR Geo/ re A. Curcb/fl ATTORNEY 1965 G. R.CHURCHILL METHOD OF MAKING A BUFFING WHEEL 3 Sheets-Sheet 3 OriginalFiled May 18, 1960 INVENTOR Geo/ye R. (bu/661% FIG. 7

ATTORNEY United States Patent 3,212,819 METHOD OF MAKING A BUFFING WHEELGeorge R. Churchill, Cohasset, Mass., assignor to George R. ChurchillCompany, Inc, Hingham, Mass., a corporation of Massachusetts Originalapplication May 18, 1960, Ser. No. 29,842. Divided and this applicationAug. 23, 1962, Ser. No. 219,006

4 Claims. (Cl. 30021) This application is a division of my copendingapplication for Buffing Wheel, Serial Number 29,842, filed May 18, 1960,now abandoned.

This invention relates to a method of making a buffing wheel.

The invention has for an object to provide a novel method of making abuffing wheel embodying a novel retaining element which is particularlyadapted for supporting a ring of bufiing material and which lends itselfto rapid and economical manufacture of the buffing wheel.

Another object of the invention is to provide a method of using anannular pronged disk in the manufacture of a buffing wheel for retaininga preformed ring of bufling material compressed thereagainst in itsassembled form during subsequent operations for completing theproduction of the buifing wheel.

A further object of the invention is to provide a novel and practicalmethod of making the present buffing wheel by which the bufiing Wheelmay be rapidly and economically produced.

With these general objects in view and such others as may hereinafterappear, the invention consists in the buffing wheel and in the method ofmaking the same as hereinafter described and particularly defined in theclaims at the end of this specification.

In the drawings illustrating the preferred embodiment of the invention:

FIG. 1 is a perspective view of a pronged retaining disk employed in themanufacture of the present bufiing Wheel;

FIG. 2 is a side elevation of a buffing wheel embodying the retainingdisk shown in FIG. 1;

FIG. 3 is a cross sectional view taken on the line 33 of FIG. 2;

FIG. 4 is a cross sectional view of apparatus which may be employed inproducing the present buffing wheel and illustrating a preferred methodof forming a ring of buffing material and pressing the pronged disk intoretaining engagement with the ring;

FIG. 5 is a cross sectional view of apparatus illustrating the step ofcompleting the assembly of the buffing wheel while the ring of buffingmaterial is retained in assembled relation by the pron ged disk;

FIG. 6 is a side elevation of a modified form of buffing wheel embodyingthe pronged retaining disk; and

FIG. 7 is a cross sectional view showing a plurality of the presentbuffing Wheel sections mounted on an arbor to form a buffing roll.

In general the present invention contemplates a novel and improvedbuffing Wheel embodying a novel and improved circular pronged metal diskforming the supporting hub of the wheel. The disk is provided with acircular row of spaced toothlike prongs adjacent its outer edge arrangedsubstantially at right angles to and extending laterally from the faceof the disk, and in practice the disk, positioned in concentric relationto a preformed annular ring of buffing material, is pressed into theannular ring adjacent the inner periphery thereof to force the prongsinto the material and to compress the material to provide a partiallyassembled unit retained in its assembled relation by the retaining disk.The unit thus retained in its partially assembled relation may then be3,212,819 Patented Oct. 19, 1965 conveniently handled and placed in astapling machine where one or more circular rows of staples are pressedthrough the 'buffing material and clinched over the metal disk topermanently secure the buffing ring to the disk and thus complete thebufiing wheel section.

Referring now to the drawings and particularly to FIG. 2, the buffingwheel therein illustrated comprises a flat ring of buffing material 10produced by winding a relatively wide strip of flexible buifingmaterial, such as a bias cut fabric, into cylindrical form, collapsingthe cylinder midway between the ends of the cylindrical structure andthen flattening the structure to present opposed faces into superimposedrelation to form an annular flat bufling element, U-shaped in crosssection, as indicated in FIG. 3. The ring 10 of bufling material issecured to a central disk comprising a hub member indicated generally at12 for assembly on an arbor or shaft, and in accordance with the presentinvention the hub member comprises a circular sheet metal retaining diskor center having an arbor hole or central opening 14 defined by acircular rim 16. Adjacent the outer marginal edge of the disk isprovided a circular row of circumferentially spaced toothlike prongs 18extending substantially at right angles from the face of the disk. Asshown in FIG. 1, the pointed triangular prongs may be formed by stampingout portions of the metal disk, and the prongs are disposed in a circlepreferably spaced inwardly from the outer periphery of the disk leavingan outer band or marginal portion 20 of metal extending beyond the rowof prongs. The prongs may preferably be slightly downwardly inclined.The disk is also provided with a plurality of radially extended,relatively shallow die-set strengthening ribs 22 and with a plurality ofcircumferentially spaced air circulating openings 24. Spaced portions ofthe disk adjacent the row of prongs 18 are provided with relatively deeparcuate die-set portions comprising spacing ribs 26 for a purpose whichwill presently appear.

As illustrated in FIGS. 2 and 3, the retaining disk 12 is arrangedconcentrically with relation to the preformed ring 10 of 'bufiingmaterial. In order to retain the ring 10 of bufling material in itspreformed condition and to maintain the predetermined inside diameter ofthe inner periphery of the ring constant, the prongs 18 are driven at aslightly downwardly inclined angle and with substantial force into thefabric adjacent the inner periphery of the ring, thus forming apartially assembled unit 0&- pable of being handled during subsequentoperations without displacement or distortion of the assembly. Inpractice, to complete the bufiing wheel, one or more circular rows ofstaples, herein shown as two rows 28, 30, are then driven into thefabric structure and through the metal disk, the staples being clinchedover the metal disk, as shown, to complete the assembly of the buffingwheel section. As illustrated, one row 28 of staples is driven throughthe band 20 beyond the circular row of prongs 18, and the other row ofstaples 30 is driven into the disk within the circular row of prongs 18.

Referring now to FIG. 4, illustrating one form of apparatus which may beused in producing the present bufling wheel, the cylindrical member 40comprises a stationary drum, and the member 42 comprises alongitudinally movable sleeve mounted on a hollow shaft 44. The outsidediameter of the sleeve is the same as the outside diameter of the drum,and the facing edges of the drum and the sleeve, respectively, arerounded as indicated at 45. In operation the sleeve is moved to apredetermined spaced distance from the drum, and a strip of bias cutfabric indicated at 46 may be wound about the drum and the sleeve in acentral position relative to the space 48 formed between the face of thedrum and the end of the sleeve. The strip is thus wound into cylindricalform, and when a 'ness of the ring free of the retaining prongs.

suitable number of plies of material has been wound about thecooperating sleeve and drum elements provision is made for contractingthe fabric cylinder medially thereof to draw the material down forming aring of boiling material having a predetermined inner periphery. Thecontracting mechanism may comprise any of the so-called iris type ofcontracting mechanisms wherein arcuately shaped and pivoted armsindicated generally at 50 are caused to engage and contract the materialmedially of the cylinder, the material being urged inwardly down betweenthe sleeve and the drum to form the continuous ring of buffing element10. In practice the contracting or drawing-down operation may beterminated at a predetermined .point to produce a ring having apreselected inside diameter which is maintained constant by the prongsof the disk 12, the inside diameter being indicated in broken lines inFIG. 4.-

Provision is then made for pressing the prongs 18 of the prongedretaining disk 12 into the marginal edge of the ring 10 adjacent theinner periphery thereof to hold and retain the preformed ring of buffingmaterial in its partially assembled form. As illustrated in FIG. 4, themember 52 comprises a movable drum forming a part of a press and isarranged to support a retaining disk 12 in concentric relation to thering 10. As shown, the face 54- of the drum may be recessed to form apocket in which the disk may be retained with the prongs 18 extendedoutwardly from the face. The drum 52 may also be provided with a centralhub portion 56 over which the rim 16 defining the central opening of thedisk is placed. The movable drum 52 may be operatively connected to thepiston 58 of a pneumatic or hydraulic cylinder, not shown, and inoperation the pronged retaining disk 12 is pressed against the preformedring of buffing material with considerable force such that the prongs 18are caused to penetrate into buifing material adjacent the contracted ordrawn-down inner periphery thereof while the ring of material issupported against the face 41 of the stationary drum 40 to retain thering 10 in its partially assembled form and to particularly maintain theinside diameter of the ring at its contracted or drawn-down dimension byholding the same against its tendency to expand without utilizingauxiliary clamping or holding means during subsequent handling of thering and during the stapling operation wherein assembly of the buffingwheel is completed.

As herein illustrated, the prongs 18 are of a length such as to extendthrough about one-half or slightly more than one-half of the thicknessof the ring of buffing material, leaving the other approximatelyone-half of the thick- However, it was found in practice that thepressure applied to the annular structure of buffing material during thedriving of the prongs into the material was such as to so firmlycompress and compact the ring of buffing material adjacent the innerperiphery that the ring will retain its compressed condition whenremoved from the press. Incidental to the stamping operation in formingthe prongs 18, the extreme ends or points thereof are deformed slightlyto provide relatively small hooks, as indicated at 19, and while thehooks are not large enough to deter the passage of the prongs into thebuffing ring when pressure is applied, as described, yet after theprongs are inserted the hooks 19 assist in urging the prongs into aclinched-over position and also serve to resist withdrawal of the prongsfrom the ring.

It will be understood that in practice the retaining disk 12 is placedin the recessed pocket on the face 54 of the drum 52 prior to the fabricwinding operation and at a time when the sleeve member 42 is in aretracted position, the drum 52 also being in a retracted position atthis time. Thereafter, the sleeve 42 is moved into predetermined spacedrelation to the stationary drum 40, and the strip of fabric is woundabout the spaced members whereupon the medial portion of the fabriccylinder is drawn down as described. It will .3 50 h Understood that thecontracting arms may be removed after the initial engagement of theprongs 18 with the fabric during the assembling and compressingoperation. The sleeve member 42 and the drum 52 may then be retractedand the partially assembled disk and ring unit may be removed. It willbe further understood that while the disk 12 is described primarily as aretaining member, it will be apparent that it also serves together withthe staple fasteners as a hub securing member to resist separation ofthe plies of the butfing ring during the commercial operation of theassembled buffing wheel unit.

The partially assembled and compactly compressed unit may then be placedin a stapling machine, as illustrated in FIG. 5, which includes a basemember provided with an upstanding central stud 62 over which thecentral opening defined by the rim 16 of the disk is fitted. A portionof the base is provided with an anvil 64 for cooperation with a staplinghead diagrammatically indicated at 65. In operation the stapling head 65may be aligned relative to the assembled unit to apply a row of staples28 on one side of the circular row of prongs 18, the buffing wheelsection being rotated through a small arc between successive staplingoperations to space the staples as shown in FIG. 2. Thereafter, thestapling head 65 may be aligned to apply a row of staples 30 on theother side of the prongs 18 as indicated in FIG. 5.

As illustrated in FIG. 7, a plurality of bufling wheel sections '70 thusformed may be mounted side by side on an arbor 72 to form a bufl'ingroll or bufling surface, the sections being clamped longitudinally ofthe arbor to complete the roll. When thus assembled, it will be seenthat the arcuate die-set portions 26 of one section bear against theface of the ring of fabric of an adjacent section at a pointsubstantially in alignment with the row of prongs 18 to serve as spacingmembers providing an air space between adjacent sections. Thus, inoperation air is permitted to circulate between adjacent sections forcooling purposes by virtue of the openings 24 in the disks and thespaces 74 formed by the arcuate die-set elements 26.

Referring now to FIG. 6, in a modified form of the present buffingwheel, the ring of bufiing-material may comprise a plurality of radiallyextended bufiing elements indicated at connected together at their innerends, preferably by weaving wires 82 extending around adjacent buflingelements to form the ring indicated generally at 84. The ring ofindividual buffing elements thus formed may be supported against thefront face 41 of the stationary drum 40 in concentric relation to theretaining disk 12, and the disk is then pressed against the ring withconsiderable pressure to cause the prongs 18 to extend into the buffingelements in the manner above described to form a partially assembledunit which may be handled without displacement of the parts during thesubsequent stapling operation. In practice the ring 84 may be supportedon the drum 40 in concentric relation to the disk 12 in any usualmanner, such as by a circular ridge, not shown, extended from the face41 and of a size such as to fit within the inside diameter of the ring84.

From the foregoing description it will be seen that the present buffingwheel embodies a novel hub member adapted to serve as a retaining diskfor maintaining the ring of bufiing material in assembled relation withthe disk during subsequent handling thereof to perform the staplingoperations without the use of auxiliary clamping elements. It will alsobe observed that the present buffing wheel may be rapidly andeconomically produced to provide an efficient and superior butfing wheelwhich may be used with advantage for a wide variety of buffing purposes.

While the preferred embodiment of the invention has been hereinillustrated and described it will be understood that the invention maybe embodied in other forms within the scope of the following claims.

Having thus described the invention what is claimed is:

1. In the method of making a bufiing wheel section of the characterdescribed the steps comprising. winding a strip of bufling materialabout spaced cylindrical elements to provide a multi-ply cylindricalstructure contracting the cylindrical structure about a medial line andinto the space between the elements to provide a flat ring structureU-shaped in cross section supporting a retaining disk having a circularrow of laterally extending prongs adjacent its outer periphery in apress and in concentric relation to the ring with the prongs directedtoward the marginal portion adjacent the inner periphery of the ringthen compressing the disk and the ring together with substantialpressure to cause the prongs to penetrate the ring to a depth of overone-half of the layers of the flat ring of U-shaped cross sectionwithout passing through the full thickness of the ring and to provide apartially assembled buffing wheel section including the unpenetratedportion of the ring capable of maintaining its assembled relation duringsubsequent handling without clinching said prongs, then removing thepartially assembled section from the press and permanently securing thering to the disk.

2. The method defined in claim 1 wherein the step of permanentlysecuring the ring to the disk consists in applying at least one circularrow of staples through the ring and the disk.

3. The method of making a bufling wheel section, the

steps comprising; supporting in a press, a retaining disc having a rowof laterally extended prongs adjacent its outer periphery; winding astrip of flexible bufiing material into cylindrical form, contractingthe cylinder midway between its ends and flattening the same to providea flat ring of buifing material, U-shaped in radial cross-section andhaving a tendency to expand; positioning the ring upon the prongs inconcentric relation to the disc; compressing the disc and the ringtogether with substantial pressure to cause the prongs of the disc topenetrate the marginal portion of the ring adjacent the inner peripherythereof to a depth of over one-half of the layers of the flat ringWithout passing through the full thickness of the ring to maintain thebuifing Wheel including the unpenetrated portion of the ring in itspartially assembled relation to prevent expansion during subsequenthandling, and removing the partially assembly section from the press andpermanently securing the ring to the disc.

4. The method defined in claim 3 including applying at least one row ofstaples through the ring of bufling material and the disc on both sidesof the row of prongs to permanently secure the ring to the disc.

References Cited by the Examiner UNITED STATES PATENTS 2,017,925 10/35Siefen. 2,650,861 9/53 MacFarland 300--1 2,687,602 8/54 Churchill 5l193FOREIGN PATENTS 157,225 6/54 Australia.

WHITMORE A. WILTZ, Primary Examiner.

JOHN F. CAMPBELL, Examiner.

1. IN THE METHOD OF MAKING A BUFFING WHEEL SECTION OF THE CHARACTERDESCRIBED THE STEPS OMPRISING WINDING A STRIP OF BUFFING MATERIAL ABOUTSPACED CYLINDRICAL ELEMENTS TO PROVIDE A MULTI-PLY CYLINDRICAL STRUCTURECONTRACTING THE CYLINDRICAL STRUCTURE ABOUT A MEDIAL LINE AND INTO THESPACE BETWEEN THE ELEMENTS TO PROVIDE A FLAT RING STRUCTURE U-SHAPED INCROSS SECTION SUPPORTING A RETAINING DISK HAVING A CIRCULAR ROW OFLATERALLY EXTENDING PRONGS ADJACENT ITS OUTER PERIPHERY IN A PRESS ANDIN CONCENTIC RELATION TO THE RING WITH THE PRONGS DIRECTED TOWARD THEMARGINAL PORTION ADJACENT THE INNER PERIPHERY OF THE RING THENCOMPRESSING THE DISK AND THE RING TOGETHER WITH SUBSTANTIAL PRESSURE TOCAUSE THE PRONGS TO PENETRATE THE RING TO A DEPTH OF OVER ONE-HALF OFTHE ALYERS OF THE FLAT RING OF U-SHAPED CROSS SECTION WITHOUT PASSINGTHROUGH THE FULL THICKNESS OF THE RING AND TO PROVIDE A PARTIALLYASSEMBLED BUFFING WHEEL SECTION INCLUDING THE UNPENETRATED PORTION OFTHE RING CAPABLE OF MAINTAINING ITS ASSEMBLED RELATION DURING SUBSEQUENTHANDLING WITHOUT CLINCHING SAID PRONGS, THEN REMOVING THE PARTIALLYASSEMBLED SECTION FROM THE PRES AND PERMANENTLY SECURING THE RING TO THEDISK.